1. Field of the Invention
The present invention is directed to thin, flexible material and, more particularly, to a flexible fabric having electrical energy storage and release capabilities integrally formed therewith.
2. Description of the Related Art
There are currently materials that incorporate energy releases in the form of light or heat and are powered by some external, rigid power source.
For example, Coler et al., U.S. Pat. No. 3,023,259, describes a flexible battery that is designed, in one embodiment, to wrap around a person under their clothing so that body heat may be utilized to maintain the electrochemical temperature within a preferred temperature range. The flexible battery includes a flexible electrode that incorporates a wire mesh selected of a metal non-reactive with components of the electrochemical system. A coating composition is provided that includes an active electrode material, electrically conductive particles, and a synthetic resin binder. Coler et al. teach the use of heat to maintain the flexible battery within a preferred operating temperature range.
Armbruster, U.S. Pat. No. 3,535,494, illustrates the use of metal foil material that is flexible and includes a layer of plastic material and small particles of electrically conductive material substantially uniformly distributed throughout the layer of plastic material. A low voltage supply provides electric current that passes in a direction substantially normal to opposing faces through the sheet material and in which the sheet material and the metal foils thereto are sandwiched between a pair of plastic sheets to form with the latter a flexible heating unit.
Romaniec, U.S. Pat. No. 3,627,988, describes electrical heating elements utilizing conducted carded fibrous carbon web having flexible electrodes and a supporting layer of loosely woven fabric overlying and united with each face of the web.
Lehovec et al., U.S. Pat. No. 4,470,263, is entitled “Peltier-Cooled Garment” that attaches to a garment and having a cold plate bearing against the skin of a user. Heat collected by the cold plate is distributed through fins.
Triplett et al., U.S. Pat. No. 4,700,054, describe electric devices formed of a fabric prepared from at least one electrode and a substance of high resistance and to include a conductive polymer. The positive temperature coefficient of the resistance material has a resistivity that increases by a factor of at least 2.5 over a temperature range of 14° C. or by a factor of at least 10 over a temperature range of 100° C., and preferably both.
Nagatsuka et al., U.S. Pat. No. 5,242,768, is directed to a three-dimensional woven fabric for use inside of a battery. The fabric material itself is not a battery and would be incapable of storing electricity. It is designed to be used in a seawater battery containing an electrolyte.
Schneider et al., U.S. Pat. No. 5,269,368, is directed to a rechargeable temperature regulating device for controlling the temperature of a beverage or other object that utilizes fluid housed in a flexible jacket having an inner chamber. The jacket is recharged in a freezer or heated in a microwave, depending on the function to be performed.
Jones, U.S. Pat. No. 6,049,062, describes a heated garment with a temperature control that is worn on the body of an individual. The thermal garment includes an interior liner with a heating element disposed in the interior liner of the garment. The heating element is disposed within a majority of the area of the garment, and at least one flexible rechargeable battery is disposed within the interior liner of the thermal garment. A thermostat within the outer layer of the thermal garment and in communication with the heating element regulates the temperature.
Aisenbray, U.S. Publication No. 2004/0188418, discloses low cost heating devices manufactured from conductive loaded resin-based materials. Micron conductor fibers are provided, preferably of nickel plated carbon fiber, stainless steel fiber, copper fiber, silver fiber, or the like. Conductive loaded resin-based heating devices can be formed using methods such as injection molding, compression molding, or extrusion. The conductive loaded resin-based material that forms the heating devices can also be in the form of a thin flexible woolen fabric that can be readily cut to the desired shape.
Knoerzer, U.S. Pat. No. 6,637,906, discloses a flexible electroluminescent (EL) film that incorporates the battery directly into the thin film layer structure and would be used for lighted product packaging. The EL films or thin film electroluminescents (TFELs) described by Knoerzer are inorganic and consist of phosphor particles that illuminate when energized by electrical current. Knoerzer describes an inverter to change DC current from the battery into AC current which is used to illuminate the EL film. With the introduction of organic light emitting polymers (LEPs) and organic light emitting diodes (OLEDs), which are organic polymers, not phosphor films, there is no need for an inverter system, which is problematic to integrate into a completely flexible system. The manufacture of the organic polymers also presents several processing advantages over an inorganic EL film.
However, there is not currently a single fabric available to the engineer or designer that has the electrical energy storage aspect directly integrated into it and is still thin, flexible, and can be manufactured into a product with the same ease as conventional fabrics. Hence, there is a need in this day and age for such a fabric that also has all the normal characteristics of a modern engineered fabric, such as waterproof, breathability, moisture wickability, stretch, color and texture choices. So far no fabric has emerged with all these characteristics.